as a spoil of war, you helped return the art to its rightful owners. >> unique in the history of civilization. >> reporter: no country had ever done that before. >> they supervised the return of 5 million, 5 million stolen objects to the countries from which these things were taken. >> reporter: paintings were returned to museums. >> there it is. >> reporter: works you can see today. >> parc monceau. this claude monet painting is one at the new york metropolitan museum of art along with this van goyen landscape and soap bubbles. hitler wants this one. >> he wants the best of the best of the things he decides are the best. >> reporter: the nazis not only stole from museums but also from thousands of families. to recover the possessions including the artwork of families just like yours must have really connected with you? >> absolutely. i ended up being able to come along and recover my grandfather's collection of 3,000 prints, some of them are hanging in my apartment right now. >> reporter: this was rye of works stolen by the nazis have still never been f like rafael's portrait of a young man.